Encapsulated Cu clusters in Zr-Beta zeolite as an efficient catalyst to promote the formation of methyl acetate from methanol

The direct conversion of methanol, a cheap and readily available feedstock, into value-added methyl acetate (MA) is a promising route. Considering the MA formation mechanism is complex, the design of highly selective catalysts is a huge challenge. Herein, we report a Cu@Zr-Beta catalyst, encapsulated Cu metal clusters within Zr-Beta zeolite by an in-situ two-step hydrothermal method, which exhibits high dispersion of Cu species and strong metal-support interaction between Cu and framework Zr species. The formation rate of MA using the Cu@Zr-Beta catalyst is as high as 2.84 mol kg cat -1 h −1 with a methanol conversion of 8.7 % and a MA selectivity of 55.8 % at 240 °C, which outperforms comparison catalysts. Experimental and characterization studies confirm that the electronic interactions between the encapsulated Cu species and Zr atoms not only enable the production of abundant and stable Cu + species but also promote the synergistic effect between Cu + and framework Zr species, thus accelerating the conversion of methanol to MA. In-situ FT-IR and reaction results show that the Cu 0 site is responsible for the dehydrogenation of methanol to CH 2 O*, which then moves to Cu + -Zr(OSi) 4 site and couples with CH 3 O* to form CH 3 CHO*, and finally produces MA through C-O coupling with another CH 3 O*.